@charlie-ellis As @mac_editor said this is the software workaround for Thunderbolt 1 and 2 Macs to use external GPU feature in 10.13.4. The Thunderbolt 3 to Thunderbolt adapter is a hardware piece that's a prerequisite to connect components.

Has anyone tested this with the late 2012 iMac that only has the Nvidia 680MX dGPU (no intel integrated GPU)? I could never get my eGPU (Sonnet Breakaway Dev Kit w/ AMD 580) working properly. My external display would show an image utilizing the eGPU, but the entire machine would slow to a crawl. Nervous to try again now that there's a workaround.

To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.